1. Field of Invention
This invention relates to a polymer of 1,2,4-thiadiazole that is especially effective as an additive in lubricants that enable the lubricants to withstand extremely high pressure and yet maintain antiwear properties. This invention also comprehends a lubricant composition containing such a polymer.
2. Description of the Prior Art
Polymers containing thiadiazole rings are known in the art. Minoura et al. (Chem. Abstracts, Vol. 68, 96241g, 1968), for example prepared poly(2,5-dithio-1,3,4-thiadiazole) and observed that the thermal stability of the polymer was, however, unsatisfactory. Polymers of 1,2,4-thiadiazole of this invention were not found in the prior art. However, non-polymeric disulfides of 1,2,4-thiadiazoles are known. For example, see U.S. Pat. Nos. 3,904,537, or 3,821,236 and 3,904,619. These compounds are not known to have the high-pressure, antiwear properties of the instant invention.
Many lubricants which are satisfactory for ordinary lubricating applications do not provide adequate protection under extremely heavy load conditions, such as metal deformation, cutting and grinding, gear lubrication of heavy duty machineries, and in bearing lubrication under severe conditions. Present lubricants made for these purposes include sulfurized and chlorinated hydrocarbon oils and oils containing such additives as molybdenum disulfides, tungsten sulfides, heavy metal salts of dialkyldithiocarbamic acids and dialkyldithiophosphoric acids, and organic and inorganic lead compounds.